
from __future__ import absolute_import

import re, stat, sys

from bup import options, git, vfs
from bup.compat import argv_bytes
from bup.helpers import chunkyreader, log, saved_errors
from bup.io import byte_stream
from bup.repo import LocalRepo

optspec = """
bup cat-file [--meta|--bupm] /branch/revision/[path]
--
meta        print the target's metadata entry (decoded then reencoded) to stdout
bupm        print the target directory's .bupm file directly to stdout
"""

def main(argv):
    o = options.Options(optspec)
    opt, flags, extra = o.parse_bytes(argv[1:])

    git.check_repo_or_die()

    if not extra:
        o.fatal('must specify a target')
    if len(extra) > 1:
        o.fatal('only one target file allowed')
    if opt.bupm and opt.meta:
        o.fatal('--meta and --bupm are incompatible')

    target = argv_bytes(extra[0])

    if not re.match(br'/*[^/]+/[^/]+', target):
        o.fatal("path %r doesn't include a branch and revision" % target)

    repo = LocalRepo()
    resolved = vfs.resolve(repo, target, follow=False)
    leaf_name, leaf_item = resolved[-1]
    if not leaf_item:
        log('error: cannot access %r in %r\n'
            % (b'/'.join(name for name, item in resolved), target))
        sys.exit(1)

    mode = vfs.item_mode(leaf_item)

    sys.stdout.flush()
    out = byte_stream(sys.stdout)

    if opt.bupm:
        if not stat.S_ISDIR(mode):
            o.fatal('%r is not a directory' % target)
        _, bupm_oid = vfs.tree_data_and_bupm(repo, leaf_item.oid)
        if bupm_oid:
            with vfs.tree_data_reader(repo, bupm_oid) as meta_stream:
                out.write(meta_stream.read())
    elif opt.meta:
        augmented = vfs.augment_item_meta(repo, leaf_item, include_size=True)
        out.write(augmented.meta.encode())
    else:
        if stat.S_ISREG(mode):
            with vfs.fopen(repo, leaf_item) as f:
                for b in chunkyreader(f):
                    out.write(b)
        else:
            o.fatal('%r is not a plain file' % target)

    if saved_errors:
        log('warning: %d errors encountered\n' % len(saved_errors))
        sys.exit(1)
